Patent GB-873782-A (GB)
Title: Fluid pressure controlled apparatus
IPC: F15C3/02
Filed: 1958-06-17
Abstract: 873,782. Calculating apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 17, 1958 [June 17, 1957], No. 19394/58. Class 106 (1). Fluid-pressure controlled apparatus comprising a plurality of piston slide members each movable to one or more of a plurality of predetermined points within a guiding channel, and having driving surfaces and controlling edges, includes controllable junction channels connecting spaced points in at least one of the guiding channels to a plurality of fluid ducts adapted to be supplied with fluid at different pressures so that the piston slide member within said one guiding channel can be moved to one of said predetermined positions by selectively controlling said junction channels to cause variation of the distribution of fluid pressure along said one guide channel. Fluid pressure controlled shift registers, counters and multivibrators are described. Shift register cell.-Fig. 2. A two-place cell comprises two valves 6, 7, each comprising a doubled piston slide 8 having an upper and a lower stable position and joined through throttles 9, 10 to the pressure side of a fluidpressure source. The two valves are connected through junction ducts 11, 12 and are connected to a common return lead 13. By connecting the lead 13 alternately to leads 14, 15, information is transmitted along the chain of cells composing the shift register. The valve 6 controls the valve 7 to assume the same position as itself. Thus, assuming the lead 13 to be connected to the lead 14 while the lead 15 is closed or connected to high pressure, the valve 7 is brought to the same position as the valve 6, for if the valves are as shown in Fig. 2, high pressure prevails on both sides of the slide 8 of the valve 6 which is therefore in stable equilibrium but due to the flow of fluid through leads 11 and 14, the pressure above the slide 8 of the valve 7 is lowered to move the slide up. If now the lead 13 is connected to the lead 15, the slides remain in the upper positions, but if the valve 6 of the next cell (not shown) is in the lower position, flow along the duct 8a joining the cells results in reduced pressure above the lowered valve, whose slide and consequently that of its associated valve 7, moves upwards. In a modification (Fig. 7, not shown), additional leads and an auxiliary slide valve are provided which ensure that the valve exercising the control function remains in stable equilibrium. In another modification, Fig. 8, two adjacent cells of a five-position shift register are shown. Each cell comprises two valves 34, 35 each having a piston slide with a hollow large portion 34 apertured at 45 and a small portion 36, the slide having five equilibrium positions. Control leads 46, 47 are selectively connected to the return lead (not shown). If for instance the lead 46 is connected to the return lead, fluid flows from the high pressure lead 39 through a throttle 37, duct 41, the aperture 45 and the lead 46, the resulting pressure drop across the throttle 37 causing the slide of the valve 35, to be moved down until the small portion 36 shuts off the duct 41. If the lead 47 is now joined to the return lead, the first valve 34 of the second cell is brought to its lower position. Counters.-A two-position counter, Fig. 9, comprises two three-part valves 48, 49, a third impulsing three-part valve 50, input leads 51, 52, output leads 53, 54 and return leads 55, 56. Assuming that initially all the slides are in the lower position, that the input 51 is connected to the return lead and that the input 52 is closed, all the slides remain at rest. If now the input 52 is joined to the return lead and the input 51 is closed, the valve 50 moves up, causing the valve 48 also to move up. The output 53 is now joined to the return lead 55 (arrow d) and the output lead 54 is closed. If now the connections to the inputs 51, 52 are reversed, the valve 50 is displaced to its lower position. Flow indicated by arrow # now displaces the valve 49 to its upper position, the arrow g showing that the' output 53 remains connected to the return lead while the output 54 is closed. When subsequently the input 51 is closed and input 52 connected to the return lead, the valve 50 is again raised, and the valve 48 is lowered. The output 54 is now connected to the return lead 55 (arrow i), while the output 53 stays closed. If now the input 51 is again joined to the return lead and the input 52 closed, then the valve 50 is again brought to its lower position. Flow indicated by arrow k brings the valve 49 to its lower position, so connecting the output 53 with the return lead 55. A five-position counter derived from the five place shift register of Fig. 8 is also described. Multivibrators.-Various examples of multivibrators are described. As shown in Fig. 11, a multivibrator having two slide-valves comprises two pressure lead inlets 69, 70 which each lead via two throttles to both ends of two valves 71, 72, return leads 73, 74 being provided. Assuming the valves to be initially in the positions shown, flow from the inlet 70 via channel 77 to the outlet 73 causes a pressure drop which moves the slide of the valve 72 to the right, thereby connecting the inlet 69 via channel 75 with the return lead 74. The slide of the valve 71 therefore moves to the left. Flow along the channel 76 now moves the slide 72 to the left, whereupon a way is opened for flow along the channel 78 to return the upper slide 71 to the right. This cycle is repeated indefinitely.